How do I remove the gear housing cover (on propeller shaft behind propeller) to check condition of the oil seal? Does it spin off counter-clockwise. I tried that without having the correct wrench but it would not budge. Is it O.K. to spray a powerful penetrant (PC Blaster) into the space around the circular edge or will that solvent be too strong and damage the oil seal?
I will take a look at my Wizard Super 5 to see if I can better help you, but what you are doing sounds like the right approach (that's what I have done on my other outboards). As far as PB Blaster....I couldn't have worked on my Super 5 if it wasn't for that stuff. I can't imagine that it would hurt a seal.
Before you go to the trouble of breaking down the lower unit, have you drained the lower unit lube? When draining it, if it comes out milky, that would indicate that water is getting in the lower unit. If not, it may be okay. You may also try running it briefly in a trash can to see if you end up with a oil slick or oil around the seals. If it isn't leaking, I've been told it is best to leave it alone and just make sure to put fresh lube in. Also, make sure you are using Lubriplate #105 (available online at NAPA auto) vice conventional lower unit oils.
The motor has been in the previous owners basement for 10 years. He never did anything to it. When I tried to drain the lower unit, nothing came out but about one-half teaspoon of clear water. I fished up inside with the end of a cable tie and it came out with a coating the color of brown mustard. Yes it looked like a milky emulsion.
The lower unit looks to be a somewhat different color than the rest of the engine. I'm looking for a "quick-fix" until I decide if, when, and how to replace the seals. I thought inspection behind the gear housing cover would provide some inspiration for what to do next.
Any suggestions are appreciated,
Well, keep up the effort with the PB Blaster to get the gear housing open to inspect the prop shaft and gears. Hopefully the water hasn't rotted out the gears or shaft. Don't be too concerned if the unit is a different color. My Super 5 has a black lower unit gear housing; however the rest of it is Wizard green.
If once you get the gear housing open and find out the lower unit is shot, let me know, as I know of a parts dealer who probably has one off of a Mercury Mark 6 (the Super 5's equivalent) that he can sell you. If it is in decent shape (try just cleaning things up with fine steel wool), you can get a lower unit seal kit from East Coast Marine (oldmercs.com) - just follow the link to the 1955 Mark 6.